There remain gaps in our knowledge of the prevalence of TM disorders in the North American population. This proposal describes a pilot study of the prevalence of signs and symptoms associated with these disorders in a Canadian community. It aims to test aspects of the methods and instruments to be used in a more comprehensive study and to provide preliminary data necessary for the planning of the study. Specifically, it will ascertain response rates to requests for telephone interviews, test the reliability of the questionnaire and examination process, determine response rates to invitation for clinical examination among symptomatic and non-symptomatic groups and allow information collected at interview and during the clinical examination to be compared. A random digit dialing technique will be employed to identify a random sample of 1000 persons aged 18 years and over living in the City of Toronto. These will be interviewed using a schedule designed to elicit information on the difinitional symptoms of pain, joint sounds and limitations in mandibular movement, their severity and functional consequences. Questions on a variety of associated symptoms will also be asked. In order to test the reliability of the questionnaire, a 10% random sub-sample of those questioned will be recalled and the interview readministered. Four hundred of those interviewed will be asked to take part in a clinical examination, equal numbers being drawn at random from symptomatic and non-symptomatic groups. The examination will consist of a history, observation of mandibular movement and joint sounds, palpation of the joints and muscles of mastication and measurement of the mandibular-maxillary relationship. A 10% random sub-sample will be re-examined to check the reliability of the examination procedure. The long term aim is to undertake a longitudinal epidemiological study to document the natural history of signs and symptoms of TM disorders and to investigate the relative influence of a variety of general and local aetiological factors on the onset and course of the disorder and the seeking of treatment.